ATHERTON — Among the young string ensembles making their mark in classical music, the Danish String Quartet is the enfant terrible. It plays with an urgency that can feel dangerous, and with a unity of intention that makes familiar material stand out in bold relief, as if it were brand new territory. Friday night at the Music@Menlo festival, the group left its mark on Beethoven.

The ensemble performed his String Quartet in F major, op. 18, no. 1 — the first of his 16 quartets — in such a manner that one could practically smell the stirrings of revolution. The Adagio emerged as kin to one of the composer’s unbearably sad and mystic excursions — last gasps, extended prayers of thanks, violent out-lashings; something Beethoven might have composed toward the end of his life, instead of at age 30.

Indeed, listening to the ensemble — three of whose members have turned, or will turn, 30 this year — one got a renewed sense of what made Beethoven radical all along.

One of his great patrons was Prince Joseph Franz Maximilian Lobkowicz, scion of a Bohemian lineage dating to the 14th century. Beethoven’s first set of string quartets (there are five others in the op. 18 set, besides the F major) was dedicated to the prince, as was every one of the pieces on Friday’s program, and three of Beethoven’s symphonies, the Eroica, the Fifth and the Pastoral.

I mention this only because, while the Danes (actually, cellist Fredrik Schøyen Sjölin is Norwegian) were exposing the emotional substrata of Beethoven’s early opus, the great-great-great-great grandson of Prince Joseph Franz Maximilian was seated in the audience at the Menlo School’s Stent Family Hall, an intimate venue that resembles an Old World music salon.

He is William Lobkowicz, who was born in Boston, attended Harvard, became a real estate broker and then — in 1989, amid the breakup of the Soviet Union — moved to Czechoslovakia. He sank roots, learned to speak Czech and began to reclaim his family’s cultural and philanthropic legacy; one of his businesses now operates four family castles in the Czech Republic as tourist destinations. Friday night at the festival, he delivered a lecture (titled “A Royal Tradition”) to a sold-out audience, explaining his own story as well as his family’s history, including Joseph Franz Maximilian’s avid arts patronage, which also extended to Gluck and Haydn — and basically bankrupted the prince.

Friday, as William Lobkowicz sat in the sixth row with his wife, Alexandra, and their children, their presence tied a neat bow around the program, aptly titled “Lobkowicz Legacy.” The whole night felt like a testament to the continued relevance of the music.

The Danish String Quartet — its other members are Frederik Øland and Rune Tonsgaard Sørensen, violins; and Asbjørn Nørgaard, viola — has a tousled indie-band persona that adds to its aura. But it’s the ensemble’s group mind that counts. It permeates the quartet’s technical command and playfulness, its abundance of sound and ability to sing like a choir. All of that was evident in Hadyn’s String Quartet in G major, op. 77, no. 1, which opened the program.

In its approach to Beethoven’s String Quartet no. 10 in E-flat major, op. 74 (“Harp”), the group made some bold decisions in regard to tempo and phrasing. But more important was that unanimity of intention, the groupthink, which created clarity and fresh impact — in the startling sound of a unison chord or the breathy flow of the Allegro’s coda, for example. This is a group that makes you listen.

The program also included “An die ferne Geliebte” (“To the Distant Beloved”), Beethoven’s song cycle, a setting of six poems by Alois Jeitteles. Baritone Randall Scarlata and pianist Gilbert Kalish delivered these love songs with idiomatic comfort and elegance. As a listener, it was hard not to fall into the yearning and romance of it all: Kalish’s voicings were just right, bringing out the melodies that Scarlata sang with such fragrant sound. The duo was a storytelling partnership.

The program was to repeat Saturday at Menlo-Atherton High School’s Center for Performing Arts. Music@Menlo continues through Aug. 9.

Richard Scheinin covers residential real estate for the Bay Area News Group. He has written for GQ and Rolling Stone and is the author of Field of Screams: The Dark Underside of America’s National Pastime (W.W. Norton), a history of baseball. During his 25-plus years based at The Mercury News, his work has been submitted for Pulitzer Prizes for reporting on religion, classical music and jazz. He shared in the Pulitzer Prize awarded to the Mercury News staff for coverage of the Loma Prieta earthquake. He has profiled hundreds of public figures, from Ike Turner to Tony La Russa.